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  1. #26
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    Quote Originally Posted by Kerry Irons View Post
    You're trying to infuse this "problem" with issues that are tangential at best. Re-read what CX said in his first post: when you backpedal, there is no derailleur keeping the chain from trying to align with the front ring so it will naturally try to get the chain on a smaller cog. It makes virtually no difference what your setup is. Get that in your head and stop backpedalling. Not sure why you are backpedalling in the first place.
    I got it now, and have confirmed what CX and you just said.
    I'm not backpedaling intentionally. But sometimes at a stop I backpedal half a rev to unclip and put my foot down. I have 4 other bikes that don't do this in big-big, only this one bike, so I never thought about it until now on this bike.

  2. #27
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    Quote Originally Posted by Jay Strongbow View Post
    Does your bike have really short chain stays?

    My experience with two identical groups on different bikes indicates short chain stays is a factor.
    I don't think it's anything to 'fix' per se. It just happens and really isn't a problem.
    chainstays are 401mm. When I'm in big-big, with 52t chainring upfront and largest cog 32t on back, the chainline angle does look a tad more extreme than all my other bikes, which have 405-410mm chainstays. So probably this is the dominant a factor causing all this. It is what it is. Need to just not backpedal when in big-big

  3. #28
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    Quote Originally Posted by aclinjury View Post
    SRAM was designed for it? how? Like CX said, there is no guide (eg, a pulley guide) to keep the chain rolling straight when its moving backwards like there is a lower pulley to guide it straight when moving forward. I would think that chainline is the main determinant if a chain will jump when backpedaling, and chainline will depend on bike geometry (eg, chainstay length)
    I was referencing cross chaining, sram red 22 is stated to work with all 22 gears.

  4. #29
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    Quote Originally Posted by cxwrench View Post
    This is complete bullshit, I really wish people that post this would stop. EVERY modern drivetrain is designed to work in big/big.
    But not if he shortened the chain to it's limit, then added larger cogs...which it seems he did.
    "L'enfer, c'est les autres"

  5. #30
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    Quote Originally Posted by Lombard View Post
    Pretty much, yes. If it spins freely in large/large, it's OK in my definition. But remember, I'm the guy who favors small/small over large/large.
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  6. #31
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    Quote Originally Posted by Lombard View Post
    Pretty much, yes. If it spins freely in large/large, it's OK in my definition. But remember, I'm the guy who favors small/small over large/large.
    Probably fine on a steel or Ti bike where the hanger is part of the frame. Not so fine to stress a light alloy hanger. They can fatigue and eventually break (even from routine use without any extra force to squeeze into big/big) and that added stress won't help them last any longer.

  7. #32
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    Quote Originally Posted by Jay Strongbow View Post
    Probably fine on a steel or Ti bike where the hanger is part of the frame. Not so fine to stress a light alloy hanger. They can fatigue and eventually break (even from routine use without any extra force to squeeze into big/big) and that added stress won't help them last any longer.
    So you're saying a looser chain is easier on the derailleur hanger? This would be another reason not to use large/large if this is the case. But I doubt it makes any real world difference.
    "With bicycles in particular, you need to separate between what's merely true and what's important."-- DCGriz, RBR.

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  8. #33
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    Quote Originally Posted by Lombard View Post
    So you're saying a looser chain is easier on the derailleur hanger? This would be another reason not to use large/large if this is the case. But I doubt it makes any real world difference.
    Large\large don't hurt nearly as much as many would have us believe.
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  9. #34
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    Quote Originally Posted by Lombard View Post
    So you're saying a looser chain is easier on the derailleur hanger? This would be another reason not to use large/large if this is the case. But I doubt it makes any real world difference.

    No. There is no such thing as a 'looser' chain if you are not going to the limits of the der. spring which is the smart way to measure your chain. The der. keeps chain tension constant in any gear. But when you go "all the way forward" as CX phrased it and you seem to think is fine you stress the hanger.

  10. #35
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    Quote Originally Posted by velodog View Post
    Large\large don't hurt nearly as much as many would have us believe.
    I didn't say it would hurt. My point is that for most of us, it's impractical and unnecessary.

    Quote Originally Posted by Jay Strongbow View Post
    No. There is no such thing as a 'looser' chain if you are not going to the limits of the der. spring which is the smart way to measure your chain. The der. keeps chain tension constant in any gear. But when you go "all the way forward" as CX phrased it and you seem to think is fine you stress the hanger.
    I see your point here. However, if you never use large/large, it's basically irrelevant.
    "With bicycles in particular, you need to separate between what's merely true and what's important."-- DCGriz, RBR.

    “Statistics are like bikinis. What they reveal is suggestive, but what they conceal is vital.” -- Aaron Levenstein



  11. #36
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    Quote Originally Posted by Lombard View Post

    I see your point here. However, if you never use large/large, it's basically irrelevant.
    With a choice between cutting my chain correctly and not being able to use all the gears I'm carrying around I'd just cut my chain correctly. But whatever works for you.

  12. #37
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    Quote Originally Posted by Lombard View Post
    Pretty much, yes. If it spins freely in large/large, it's OK in my definition. But remember, I'm the guy who favors small/small over large/large.
    Small\small holds no interest for me. I'll go large\large because that's usually short term, but finding my way to small\small usually means that the struggle is ending so I'll have shifted to the large ring before then.

    Choice is good, luckily we all get to make our own.
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  13. #38
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    Quote Originally Posted by velodog View Post
    Small\small holds no interest for me.
    I use it quite a bit on hills that start out needing the small ring, then flatten out so speed up, when I'm hanging on by the skin of my teeth and switching to big ring and rear shifting would be enough to pop me off the back.

  14. #39
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    well guys, after some further inspection of the bike, I have also ruled out that my chain is not long enough. It is long enough.

    My "issue" (which is really isn't an issue) boils down to 2 things:
    1. relatively short chainstays
    2. narrowness of 11 spd chain

    why do I say this? Because, like I mentioned before, shorter chainstays give an exaggerated chainline angle. And the narrow 11 spd drivetrain means that tolerance between cogs and chain is tight. So combine a higher chain angle with tight chain/cog tolerance, it means that backpedaling will cause the cogs to want to make the chain jump.

    On my other bikes, they're all 10 speed and with longer chainstays. And this is why I don't experience backpedal issue on the other bikes because their chains have more room to move about between the cogs (thus the cogs don't cause chain to jump). So that's that, I think I got it right, right?? Solution is don't backpedal eh. But, hey, sometimes I backpedal (by raising my foot) half a revolution to either get my foot in a ready position (3- or 9- o'clock), or I might backpedal half a rev backwards to put my foot down as I unclip. So I just have to make sure I'm not in the big chainring while also in the 1st or 2nd cogs (top biggest ones)

  15. #40
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    Quote Originally Posted by aclinjury View Post
    well guys, after some further inspection of the bike, I have also ruled out that my chain is not long enough. It is long enough.

    My "issue" (which is really isn't an issue) boils down to 2 things:
    1. relatively short chainstays
    2. narrowness of 11 spd chain

    why do I say this? Because, like I mentioned before, shorter chainstays give an exaggerated chainline angle. And the narrow 11 spd drivetrain means that tolerance between cogs and chain is tight. So combine a higher chain angle with tight chain/cog tolerance, it means that backpedaling will cause the cogs to want to make the chain jump.

    On my other bikes, they're all 10 speed and with longer chainstays. And this is why I don't experience backpedal issue on the other bikes because their chains have more room to move about between the cogs (thus the cogs don't cause chain to jump). So that's that, I think I got it right, right?? Solution is don't backpedal eh. But, hey, sometimes I backpedal (by raising my foot) half a revolution to either get my foot in a ready position (3- or 9- o'clock), or I might backpedal half a rev backwards to put my foot down as I unclip. So I just have to make sure I'm not in the big chainring while also in the 1st or 2nd cogs (top biggest ones)
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  16. #41
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    Quote Originally Posted by cxwrench View Post
    This is complete bullshit, I really wish people that post this would stop. EVERY modern drivetrain is designed to work in big/big.
    I'm certainly not an expert on bikes, (which is one reason I never work on them), but I wish what you state could be communicated to my individual bike and specifically its front derailleur.

  17. #42
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    Quote Originally Posted by GlobalGuy View Post
    I'm certainly not an expert on bikes, (which is one reason I never work on them), but I wish what you state could be communicated to my individual bike and specifically its front derailleur.
    You probably should start then because your mechanic doesn't seem to be able to handle something I'm sure you could.

  18. #43
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    Quote Originally Posted by aclinjury View Post
    So I just have to make sure I'm not in the big chainring while also in the 1st or 2nd cogs (top biggest ones)
    When I'm rolling up to a stop, I shift to the small chainring. I know I'll get away from the stop more quickly when I'm in the proper gear.

  19. #44
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    Quote Originally Posted by Kerry Irons View Post
    When I'm rolling up to a stop, I shift to the small chainring. I know I'll get away from the stop more quickly when I'm in the proper gear.
    Sounds like a no-brainer to me. Small ring and 5th cog works for me unless I'm stopped on a hill.
    "With bicycles in particular, you need to separate between what's merely true and what's important."-- DCGriz, RBR.

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  20. #45
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    Quote Originally Posted by Kerry Irons View Post
    When I'm rolling up to a stop, I shift to the small chainring. I know I'll get away from the stop more quickly when I'm in the proper gear.
    well I also have a fun habit of trying to do a track stand if I know the light is about to turn green or if I'm not planning to put a foot down at a stop, rather not muck around with front shifting

  21. #46
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    Quote Originally Posted by cxwrench View Post
    This is complete bullshit, I really wish people that post this would stop. EVERY modern drivetrain is designed to work in big/big.
    I know I use mine when necessary or whenever I feel like it and I don't spend .0000000000001 thinking about it.

    I'll use whatever combination I need to get me there. That's what those gears are there for.

    At least now I don't have to hear that chain rub anymore with the SRAM yaw FD.
    Last edited by Methodical; 04-01-2018 at 11:41 PM.

  22. #47
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    update to my post:

    well I have since changed out the 11-spd Yaban (Taiwan) chain with a Shimano 11-spd Dura Ace/XTR chain, and my issue has been COMPLETELY resolved! Amazing.

    I did measure the width of the Yaban chain and it's exactly the same width as the Shimano chain. So chain widths are the same. However, the difference (however slight) is in the pattern of the notches at the end of each link! Apparently, Shimano cassette really needs a Shimano chain for completely smooth operation. Back pedaling while completely cross-chained no longer cause any chain dropping/skipping.
    There you go. Lesson learned for me.

  23. #48
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    Quote Originally Posted by aclinjury View Post
    update to my post:

    well I have since changed out the 11-spd Yaban (Taiwan) chain with a Shimano 11-spd Dura Ace/XTR chain, and my issue has been COMPLETELY resolved! Amazing.

    I did measure the width of the Yaban chain and it's exactly the same width as the Shimano chain. So chain widths are the same. However, the difference (however slight) is in the pattern of the notches at the end of each link! Apparently, Shimano cassette really needs a Shimano chain for completely smooth operation. Back pedaling while completely cross-chained no longer cause any chain dropping/skipping.
    There you go. Lesson learned for me.
    Huh...I'm surprised that it made that much difference but glad to hear it. Good job figuring it out!
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  24. #49
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    Quote Originally Posted by cxwrench View Post
    Huh...I'm surprised that it made that much difference but glad to hear it. Good job figuring it out!
    I'm also surprised that it made that much of a difference!

    I think it made a difference in this case because in this particular case the frame has a shorter than usual chainstays (under 400mm), and this give the chainline a huge angle when crossed-chain. And couple with the tight tolerances of 11-spd drivetrain, backpedaling is no bueno! I think if the chainstays were a bit longer, like 410-415mm, then the Yaban chain would have been fine.

    So lesson for me is, when tolerances are supertight, use all components from the same manufacturer. It's amazing how much smoother the Shimano chain is now.

  25. #50
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    Quote Originally Posted by aclinjury View Post
    I'm also surprised that it made that much of a difference!

    I think it made a difference in this case because in this particular case the frame has a shorter than usual chainstays (under 400mm), and this give the chainline a huge angle when crossed-chain. And couple with the tight tolerances of 11-spd drivetrain, backpedaling is no bueno! I think if the chainstays were a bit longer, like 410-415mm, then the Yaban chain would have been fine.

    So lesson for me is, when tolerances are supertight, use all components from the same manufacturer. It's amazing how much smoother the Shimano chain is now.
    To quote myself from earlier "My experience with two identical groups on different bikes indicates short chain stays is a factor."

    Back when I was using the bike with super short chainstays I was using mostly 10 speed Ultegra chains. And now that I think of I seem to recall the skipping while backpedaling would only happen, or happen more and easier, when my chain was in need of a lube job.

    I don't know that "same manufacturer" is necessarily it and it's more like "better" (I'd guess switching to a high end KMC or Sram would have had the same results and Sora wouldn't) but whatever, I think generally you got it.

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